Publications

In this study, a compact cold sprayed (CS) Ti coating was deposited on Mg alloy using a high pressure cold spray (HPCS) system. The wear and corrosion behavior of the CS Ti coating was compared with that of CS Al coating and bare Mg alloy. The Ti coating yielded lower wear rate compared to Al coating and Mg alloy. Electrochemical impedance spectroscopy (EIS) and cyclic potentiodynamic polarization (CPP) tests revealed that CS Ti coating can substantially reduce corrosion rate of AZ31B in chloride containing solutions compared to CS Al coating. Interestingly, Ti-coated Mg alloy demonstrated negative hysteresis loop, depicting repassivation of pits, in contrast to AZ31B and Al-coated AZ31B with positive hysteresis loops where corrosion potential (Ecorr) > repassivation potential (Erp); indicating irreversible growth of pits. AZ31B and Al-coated AZ31B were most susceptible to pitting corrosion, while Ti-coated Mg alloy indicated noticeable resistance to pitting in 3.5 wt % NaCl solution. In comparison to Al coating, Ti coating considerably separated the AZ31BMg alloy surface from the corrosive electrolyte during long term immersion test for 11 days.

MXenes are an emerging class of two-dimensional (2D) transition metal carbides, nitrides, and carbonitrides with a unique combination of mechanical, electrical, and thermal properties. While MXenes have been extensively studied in electrochemical and materials science contexts, their mechanical behavior and engineering relevance remain comparatively underexplored. This paper provides a mechanically focused synthesis of MXene research, connecting structure, synthesis, processing, mechanical properties, and functional performance to engineering applications. Emphasis is placed on the tunability of tensile, elastic, shear, and thermomechanical properties through controlled variation of composition, surface terminations, and defects. Comparisons with graphene are used to clarify performance trade-offs and application-specific advantages. Key challenges, including environmental stability, moisture sensitivity, durability, scalability, cost, and integration with conventional engineering materials, are critically examined alongside current mitigation strategies. Applications in structural composites, mechanical reinforcement, energy storage, electromechanical systems, and MXene-based sensors and actuators are discussed to demonstrate practical relevance. By framing MXenes as engineerable materials rather than isolated nanomaterials, this work serves as a technical reference and entry point for mechanical engineers and interdisciplinary researchers seeking to design and deploy MXenes in advanced engineering systems.

Currently soft robots primarily rely on pneumatics and geometrical asymmetry to achieve locomotion, which limits their working range, versatility, and other untethered functionalities. In this paper, we introduce a novel approach to achieve locomotion for soft robots through dynamically tunable friction to address these challenges, which is achieved by subsurface stiffness modulation (SSM) of a stimuli-responsive component within composite structures. To demonstrate this, we design and fabricate an elastomeric pad made of polydimethylsiloxane (PDMS), which is embedded with a spiral channel filled with a low melting point alloy (LMPA). Once the LMPA strip is melted upon Joule heating, the compliance of the composite structure increases and the friction between the composite surface and the opposing surface increases. A series of experiments and finite element analysis (FEA) have been performed to characterize the frictional behavior of these composite pads and elucidate the underlying physics dominating the tunable friction. We also demonstrate that when these composite structures are properly integrated into soft crawling robots inspired by inchworms and earthworms, the differences in friction of the two ends of these robots through SSM can potentially be used to generate translational locomotion for untethered crawling robots.

The degradation due to high friction, wear, and corrosion of mechanical components for industrial applications has invoked substantial economic loss. In recent years, scientists and engineers have developed techniques to mitigate the issues associated with this deterioration potentially. Among these developed techniques, controlling the coefficient of friction (COF), wear rate, and corrosion using laser shock peening (LSP) is a preeminent and popular innovation. This paper aims to summarize the existing literature on the LSP of steels, discuss the current state-of-the-art LSP, and demonstrate the mechanisms that dictate the enhanced tribological and corrosion properties. More specifically, the influence of LSP on COF, wear rate, corrosion potential, surface hardening, and surface morphological changes on various materials used for aerospace, automotive, biomedical, nuclear, and chemical applications is explained. In addition, grain refinement and the gradient microstructure formation during LSP are discussed. Additionally, recent advances and applications of LSP are elucidated.